California became the first U.S. state to join the World Health Organization's (WHO) Global Outbreak Alert and Response Network (GOARN) on Friday, one day after the United States officially withdrew from the WHO.

California Governor Gavin Newsom announced the decision following a meeting with WHO Director-General Tedros Adhanom Ghebreyesus at the World Economic Forum in Davos, Switzerland, said a statement from the governor's office.

The GOARN is a WHO-coordinated international network that brings together hundreds of public health institutions, governments, laboratories, academic centers and response organizations worldwide to rapidly detect and respond to emerging health threats, particularly those with cross-border or pandemic potential.

"The Trump administration's withdrawal from WHO is a reckless decision that will hurt all Californians and Americans," said Newsom. "California will not bear witness to the chaos this decision will bring. We will continue to foster partnerships across the globe and remain at the forefront of public health preparedness."

Newsom's office said the California Department of Public Health is currently the only state-led institution in GOARN, though several U.S.-based academic institutions and response organizations remain members of the network.

The move is part of broader public health initiatives launched by California in recent months. In December 2025, Newsom announced the Public Health Network Innovation Exchange, a California-led effort to modernize public health infrastructure.

California also partnered with Oregon, Washington and Hawaii in September 2025 to form the West Coast Health Alliance, which issues vaccine recommendations independent of federal guidance.

The United States completed its withdrawal from the WHO on Thursday, ending over 70 years of membership. The U.S. Department of Health and Human Services cited the organization's handling of the COVID-19 pandemic and "failure to adopt urgently needed reforms" as reasons for the decision.